Prompt before restarting the server if anything is playing

ui-templates/restart-confirm.html

@@ -0,0 +1,9 @@
+{% extends 'base.html' %}
+{% block content_inner %}
+    <div class="text-center">
+      <p class="lead text-gray-800 mb-2">Hang on a second!</p>
+      <p class="text-gray-900 mb-3">Something is currently playing. Restarting will interrupt it! Are you sure?</p>
+        <a href="/status" class="btn btn-info">Cancel</a>
+        <a href="/restart?confirm=true" class="btn btn-danger">Confirm</a>
+    </div>
+{% endblock %}

web_server.py

@@ -496,6 +496,11 @@ def quit(request):
 
 @app.route("/restart")
 def restart(request):
+    if request.args.get("confirm", '') != "true":
+        for i in range(server_state.get()["num_channels"]):
+            state = status(i)
+            if state["playing"]:
+                return render_template("restart-confirm.html", data=None)
     server_state.update("running_state", "restarting")
 
     data = {